WASHINGTON — Former Vice President Dick Cheney says he had a secret resignation letter stored in a safe for most of the Bush administration in case he became incapacitated.

Cheney, who is promoting a memoir, says he signed the resignation letter in March 2001, just about two months after taking office. He says only President George W. Bush and one of the vice president’s staff members knew of the letter.

Cheney says one of the reasons for having a resignation letter on hand was his history of health problems, including multiple heart attacks.